DIPHTHERIA-TOXIN FRAGMENT FORMS LARGE PORES IN PHOSPHOLIPID-BILAYER MEMBRANES
DIPHTHERIA-TOXIN FRAGMENT FORMS LARGE PORES IN PHOSPHOLIPID-BILAYER MEMBRANES
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DOI：
10.1073/pnas.78.8.4950
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发表时间：
1981-01-01
期刊：
影响因子：
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通讯作者：
COLOMBINI, M
中科院分区：
文献类型：
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作者：
KAGAN, BL;FINKELSTEIN, A;COLOMBINI, M
白喉毒素(白喉棒状杆菌)的细胞毒作用需要其酶A片段(Mw.apprxeq)进入。21,000)进入敏感细胞的胞浆。B45片段(Mw·apprxeq.24,000)，似乎在脂质双层中形成了足够大的孔(直径.18.ANG.)为了允许扩展片段A通过，当含B45的一侧在低pH(4.7)时孔道形成最大，而相反侧在高pH(7.4)时孔道形成最大。这些条件类似于存在于溶酶体膜上的pH梯度。片段A可能从酸性内吞小泡(溶酶体？)穿过这些毛孔。到细胞质中。
The cytotoxic effect of diphtheria toxin (Corynebacterium diphtheriae) requires the entry of its enzymatic A fragment (MW .apprxeq. 21,000) in to the cytosol of sensitive cells. The B45 fragment (MW .apprxeq. 24,000) seemingly forms, in lipid bilayers, pores that are large enough (diameter .gtoreq. 18 .ANG.) to allow the passage of extended fragment A. Pore formation is maximal when the B45-containing side is at low pH (4.7) and the opposite side is at high pH (7.4). These conditions resemble the pH gradient existing across lysosomal membranes. Fragment A may pass through these pores from acidic endocytotic vesicles (lysosome?) to the cytosol.